Final answer:
The horizontal distance from the point (-3,1) to the y-axis is 3 units, as the point is 3 units to the left of the y-axis.
Step-by-step explanation:
The question asks for the horizontal distance from the point (-3,1) to the y-axis. The x-coordinate of a point indicates its distance from the y-axis: a positive x-coordinate means the point is to the right of the y-axis, and a negative x-coordinate means the point is to the left. Since the x-coordinate of the point (-3,1) is -3, it is 3 units to the left of the y-axis. Therefore, the horizontal distance from the point to the y-axis is 3 units.